Two-Dimensional Structure Simulation of Size-Selective Filtration of Electrospun PVDF Piezoelectric Fiber Membrane Under Liquid Conditions

By observing the interception of micro- and nano-particles in the filtrate by the filter medium, the filtration performance of the filter medium can be intuitively reflected. But the computational costs involved in scanning the physical structure to create a 1:1 model are huge. Therefore, this paper analyzes the structural distribution parameters of the thickness direction of the filter medium and creates a two-dimensional (2D) structural model. For the first time, computational simulations based on a 2D model were conducted to investigate the size-selective filtration performance of electrospun polyvinylidene fluoride (PVDF) piezoelectric nanofiber filter materials for nano-sized silicon dioxide (SiO₂) particles, incorporating fiber distribution parameters along the thickness direction. Scanning electron microscope (SEM) was used to analyze the fiber filter, and the accurate fiber size distribution was obtained. The distribution parameters were used to randomly generate a 2D circular surface referred to as the fiber cross-section, and then the performance parameters of the used nano-SiO₂ particles were input. Finally, the multi-physical field coupling analysis and calculation of the 2D model was carried out. The interception quantity and interception distribution are compared with the experimental results. The error between the filtration effect of the obtained model and the filtration efficiency measured by the corresponding experiment is less than 0.2%. Therefore, the model can visualize the interception effect of PVDF piezoelectric fiber layer under the condition of fluid filtration and also provide a theoretical model analysis for optimizing the structural distribution characteristics of the fiber layer.

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